Long-term evolution (“LTE”) is a wireless communication standard used for high-speed data for mobile devices and data terminals. LTE-Advanced is a major enhancement to the LTE standard. Within the LTE-Advanced standard, carrier aggregation is used to increase the bandwidth, and thereby increase the bitrates. Carrier aggregation has been introduced in the 3rd Generation Partnership Project (“3GPP”) Release 10, namely, the LTE-Advanced standard, to provide wider than 20 MHz transmission bandwidth to a single device (e.g., user equipment or “UE”) while maintaining the backward compatibility with legacy UEs.
Under the current standards, each aggregated carrier is referred to as a component carrier, and each component carrier can have a bandwidth of 1.4, 3, 5, 10, 15 or 20 MHz and a maximum of five component carriers can be aggregated. As illustrated in FIG. 1, five component carriers may each have a bandwidth of 20 MHz to combine for a maximum total bandwidth of 100 MHz. With carrier aggregation features enabled, the LTE-Advanced standard may meet International Mobile Telecommunications (“IMT”) Advanced's peak downlink (“DL”) throughput requirement, or 1 Gbps.